Brahminy river turtle
|Brahminy river turtle|
The genus Hardella, to which the species Hardella thurjii belongs, is a monotypic genus.
Hardella thurjii has a shell with a large, moderately flat, dark brown or black carapace (dorsal surface) and a yellow or black plastron (ventral surface). The shell is up to 18 inches (460 mm) in length in females, and is shorter in males. The lower jaw is heavily dented.
Hardella thurjii exhibits sexual dimorphism. Mature females are three times the size of mature males. According to Das, maximum straight carapace length in females is 61 cm (24 in), but in males maximum straight carapace length is only 18 cm (7.1 in).
The reproductive habits of H. thurjii are unique among reptiles in that the females lay their eggs under water rather than on dry land. Their reproductive cycle follows seasonal changes in the water levels of the rivers in which they live. In autumn, females lay their eggs under water, where higher water levels submerge the eggs for 40 to 45 days. In the winter, lower water levels expose the eggs for five months. The rising water levels of spring submerge the almost mature eggs once again, and the turtles hatch in the river.
Indian zoologist Dhruvajyoti Basu first documented the unique reproductive habits of the brahminy river turtle in 2011. The Prague Zoo incubated the first brahminy river turtle which was born in captivity in 2012.
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